Martine N. Joseph                                                                                   Return to Biology Menu

George W. Wingate High School, Brooklyn

Living Environment

Summer 2001


Grade Level: 9th-11th 

Time Allocation: 4-45 minutes periods


How can we describe the function and characteristics of the human immune system?

Learning Objectives: At the end of this lesson students should be able to:

·        Locate and describe the functions of all organs of the immune system

·        Explain the three lines of defense against disease –causing organisms

·        Describe and understand the specificity of antibodies

·        Compare the defense mechanism of the immune system to that of a sport team or security system

·        Understand the relationship between the immune system and homeostasis i.e. diseases or disorders



1.      Projector

2.      Laptop or Computer with Microsoft Powerpoint

3.      Disk with PowerPoint demonstration slides (1-7)



Ask student if they ever had one of the following infections: Measles; Mumps; Smallpox; Chickenpox; a cold; flu. Discuss why the results are this way. Allow students to come to the conclusions that very few of them if any had the first three infections because of vaccination.  



I: What are some words that come to mind when you see the word 'Immune System'?

Prompt students to recall definition of system and to use prior knowledge to come to the definition of 'immune'.

Have a volunteer write students answers to complete this web 



Allow students to use these terms to come up with a definite function of purpose of the immune system.

II. Description of the immune system

Made of highly specialized cells and a circulatory system consisting of lymphatic nodes and lymphatic vessels.

(Describe the types of white blood cells, their origin and functions)

Demonstration: Slide I "Cells of the Immune System"

Organs of the immune system are made of lymphoid tissues hence the name lymphoid organs. These organs are positioned throughout the body.

            Demonstration: Slide II "Organs of the Immune System"

            Demonstration: Slide III “Lymphatic Vessels & Lymph Nodes”

The lymphatic vessels and lymphatic nodes are the parts of the special circulatory system that carries lymph. Lymph nodes dot the network of lymphatic vessels and provide a meeting ground for the immune system cells (White blood cells chiefly lymphocytes) 


III: What are of some of the substances or invaders that are targeted by the immune system?

Elicit: Infectious bacteria, Fungi, Parasite, and viruses. Be sure to mention allergens and cancerous cells

Demonstration: Slide IV  “Foreign Invaders”

This slide shows a picture of: Streptococci (Bacteria), mold (Fungi), schistosomiasis (Parasite), and Herpes (Virus). 

IV: How does the body defend itself against infection?

            A. 1st line of defense: Involves several kinds of physical and chemical barriers.

                        Elicit: Sweat, Tears, Saliva, Mucus (chemical barriers)

                        Elicit: Skin, membrane lining body passages (physical barriers)

            B. 2nd line of defense: The Inflammatory Response

Elicit: Swelling, redness, warmth, and pain in the area of an infection. An increased blood flow attracts White Blood Cells i.e. macrophages, phagocytes and neutrophils to infected area.

            C. 3rd line of defense: The Immune response

At this stage the immune system is fully active in recognizing, attacking, destroying and 'remembering' each kind of pathogen or foreign substances that enter the body. This step involves the production of antibodies and specialized cells that bind to and inactivate foreign substances.

Demonstration: Slide V: antibodies

The variety of antibodies is very large. Different antibodies are destined for different purposes. Some coat the foreign invaders to make them attractive to the circulating scavenger cells, phagocytes, which will engulf an unwelcome microbe.  

(Describe briefly the structure and function of antibodies)           

V: Disorders of the immune system

Describe the causes and effects of several diseases or disorders on the immune system i.e. Allergies, AIDS and Autoimmune disease. This will help students to understand the role of the immune system in helping the body to maintain a well-balanced health state. 

            Demonstration: Slide VI: Disorders of the Immune System: AIDS

When the immune system is lacking one or more of its components, the result is an immunodeficiency disorder.

Question: How can a person develop this disorder?

Elicit:  1). Inherited 

2). Acquired through infection

3). Produced as an inadvertent side effect of drugs such as those used to treat cancer or transplant patients.

           Demonstration: Slide VII: Autoimmune disorders 

Sometimes the immune system 's recognition apparatus breaks down. The body begins to manufacture antibodies and T-cells directed to against the body's own cells and organs contribute to many diseases known as autoimmune diseases.


Summary & Application

Allow students time to respond to the following critical thinking questions in writing. A class discussion could be followed.

1.     Suppose a person's immune response is operating at a below-normal level. Suggest several possible causes for this deficiency.

2.     Why do you think a person can come down with a common cold over and over again without developing immunity to it?


This lesson plan aligns with learning standards 1,2, 4, 5 and 7. It also applies to the following performance standards S2a, S2d, S4c, S7a, and S7e.